Post-cure depth of cure of bulk fill dental resin-composites

Objectives. To determine the post-cure depth of cure of bulk fill resin composites through using Vickers hardness profiles (VHN). Methods. Five bulk fill composite materials were examined: Tetric EvoCeram (R) Bulk Fill, X-tra base, Venus (R) Bulk Fill, Filtek(TM) Bulk Fill, SonicFill(TM). Three specimens of each material type were prepared in stainless steel molds which contained a slot of dimensions (15 mm x 4 mm x 2 mm), and a top plate. The molds were irradiated from one end. All specimens were stored at 37 degrees C for 24 h, before measurement. The Vickers hardness was measured as a function of depth of material, at 0.3 mm intervals. Data were analysed by one-way ANOVA using Tukey post hoc tests (alpha = 0.05). Results. The maximum VHN ranged from 37.8 to 77.4, whilst the VHN at 80% of max.VHN ranged from 30.4 to 61.9. The depth corresponding to 80% of max.VHN, ranged from 4.14 to 5.03 mm. One-way ANOVA showed statistically significant differences between materials for all parameters tested. SonicFill exhibited the highest VHN (p <0.001) while Venus Bulk Fill the lowest (p <= 0.001). SonicFill and Tetric EvoCeram Bulk Fill had the greatest depth of cure (5.03 and 4.47 mm, respectively) and was significant's different from X-tra base, Venus Bulk Fill and Filtek Bulk Fill (p <= 0.016). Linear regression confirmed a positive regression between max.VHN and filler loading (r(2) = 0.94). Significance. Bulk fill resin composites can be cured to an acceptable post-cure depth, according to the manufacturers' claims. SonicFill and Tetric EvoCeram Bulk Fill had the greatest depth of cure among the composites examined. (C) 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.